STATEN ISLAND, N.Y. -- The Fire Department has barred two paramedics and two emergency medical technicians who responded to an unconscious Eric Garner after the Port Richmond man was taken to the ground by an NYPD cop's chokehold Thursday, a source with knowledge of the situation confirmed.

The four emergency service workers, all of whom are Richmond University Medical Center employees, have been placed on modified duty and will not be going on ambulance calls pending an investigation and review of their response, the source said.

The FDNY has gotten involved because it oversees the city's 911 system.

"Sir, it's EMS. C'mon, we're here to help, all right. We're here to help you," she says. "We're getting the stretcher, all right."

An officer can then be heard saying, "He's breathing, he's got a pulse."

When an onlooker asks why no one performed CPR on the unresponsive father of six, an officer responds, "Cause he's breathing."

From the time the video begins to the time the unresponsive Garner is wheeled away on a stretcher, he is never connected to an oxygen mask.

Garner, 43, was taken to Richmond University Medical Center, West Brighton, where he was pronounced dead. Police said Garner went into cardiac arrest while they attempted to place him under arrest on charges of selling untaxed cigarettes.